Question
What do the spectral lines represent?
Answer:
Spectral lines is defined by quantum mechanics in terms of energy levels of ions, molecules, and atoms. When electrons move from a higher level to lower one, photons are emitted and an emission line can be seen in the spectrum. As electrons jump down to the n=2 orbit, they emit photons of specific frequency (hence colour) that can be seen as emission lines in the visible part of spectrum.
Explanation:
1 kg =1000 g = 10³ g,
1 m = 100 cm ,
(1m)³ = (100 cm)³= (10²)³ cm³ = 10⁶ cm³ or 10⁶ mL
5,427 kg/m³ = <span>5,427 kg/ 1m³ = (5427 * 10³ g)/ 10⁶ mL=5427/10³ g/mL=
=5427/1000 g/mL = 5.427 g/mL
</span>5.427 g/mL is density of Mercury, and 1.0 g/mL is density of water.
Density of Mercury is more then density of the water, so
mercury will sink in the water.
The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. ... Because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products.
The last choice is the equation for photosynthesis
Answer is: MgF₂, magnesium fluoride.
Magnesium fluoride is salt, ionic compound, because magnesium is metal from 2. group of Periodic table of elements and has low ionisation energy and electronegativity, which means it easily lose valence electons, fluorine is nonmetal with greatest electronegativity, which meand it easily gain electron, so magnesium cation (Mg²⁺) and fluorine anion (F⁻) are formed.
